Method of heating mandrels for rolling tubes.



'No. 70|,693.' Patented June 3, I902.

a. H. EVERSON.

METHOD OF HEATINGIANDRELS FOB ROLLING TUBES.

(Application filed Apr. 19, 1901.

(No Model.)

In I

W TN ESSES'I I INVENTCIR/ U ITED STATES PATENT OFFICE.

GEORGE H. EVERSON, OF PITTSBURG, PENNSYLVANIA.

METHOD OF HEATING MANDRELS FOR ROLLING TUBES.

SPECIFICATION forming part of Letters Patent No. 701,693, dated June 3, 1902. I

7 Application filed April 19, 1901. Serial No. 56,576. (No specimens.)

To all whom, it may concern.-

Be it known that I, GEORGE I-I. EVERSON, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Heating Mandrels for Use in Rolling Tubes, of which the following is a specification, reference being had therein to the accompanying drawing. 1

In practicing the method of rolling tubes patented to me June 10, 1890, No. 430,008, it has been found advantageous to use heated mandre1s,as'they are more readily removable from the tubes at the completion of the'rolling operation, owing to their appreciable con traction incident to cooling. With cold mandrels the tubes frequently become so tightly fixed thereon that it is with great difficulty that the mandrels are removed. Also in the] rolling of hot tubes a cold mandrel i'sliable to injuriously chill the metal-an objection not encountered in using'a heated' mandrel.

Ithas been proposed heretoforeto roll tubes on heated mandrels; but so far as I am informed no effective way has been provided for heating them. The temper of mandrels must be preserved, (otherwise'they will fiatten between the rolls,) and their essentially smooth surfaces must be maintained to avoid imperfections in the finished tubes and diffs culty in removing the mandrels therefrom.

A mandrel cannot be properly heated in a muffle or other furnace or by the direct heat ties, I submerge the mandrels in Water the temperature of which is maintained, preferably, at the boiling-point, andpermit them to remain therein until they attaimpreferably,

the same temperature as the water from cen-- ter to circumference. In this way an absolutely uniform temperature is obtained without impairing the temper of the mandrels and without injury to their essentially smooth surfaces.

In the accompanying drawing I have ilustrated in cross-section atank or tub 2, which may be employed in practicing myimproved method,containing asuitalole quantity of water which may be heated by steam introduced pairing their "temper or their essentially smooth surface, consisting in maintaining the mandrels in "a bath of heated Water until the requisite degree of heat is attained.

2. The method of heating tube-rolling mandrels without impairing their temper or their essentially smooth surface, consisting in maintainingthe mandrels in abath of heated water until they attain the same degree of heat as the water.

3. The method of heating tube-rolling man drels without impairing their temper or their essentially smooth surface, consisting in maintaining the mandrels in abath of heated water until, from center to circumference, they attain the same degree of heat as the water.

In testimony whereof I aflix my signature in presence of two witnesses.

. GEORGE I-I. EVERSON.

Witnesses: l

J M. NESBIT, ALEX. S. MABON. 

